Harvard Law School professor Elizabeth Warren, the presumptive Democratic Senate nominee in Massachusetts, raked in a whopping $5.7 million in the fourth quarter of 2011, a campaign source confirmed. &nbsp;

Brown ended 2011 with about $12.8 million in cash on hand. Warren had more than $6 million in the bank. Warren's fundraising figures were first reported by the Boston Globe.

&ldquo;From all across our commonwealth, people are supporting our campaign&nbsp;and the fight to level the playing field for middle class families,&rdquo; Warren said in a statement. &ldquo;With Wall Street lining up&nbsp;against this campaign, already contributing millions and willing to&nbsp;pay any price to try to stop our work, it&rsquo;s going to take a strong,&nbsp;grassroots effort like this to win.&rdquo;

The campaign said that the average contribution was $64.

Brown will officially launch his re-election campaign on Jan. 19, the two-year anniversary of his come-from-behind victory over state Attorney General Martha Coakley (D).

Recent polling has shown the Senate race is extremely close. Roll Call rates the contest as a Tossup.